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(Click for frequent words.) 79 X ray Observatory 68 ESA XMM Newton 68 Spitzer Space Telescope 67 Wilkinson Microwave Anisotropy Probe 66 X ray observatories 66 XMM Newton 65 orbiting Chandra 65 Space Telescope 65 NASA Wilkinson Microwave 64 X ray observatory 63 X ray telescopes 63 NASA Fermi Gamma 62 spectroscopic observations 62 RXTE 61 Fermi telescope 61 NASA Interstellar Boundary 61 astronomers 61 Infrared Array Camera 61 Fermi Gamma ray 61 Very Large Telescope 61 Very Large Array 61 ray Space Telescope 61 Chandra X ray 61 Hubble observations 60 distant supernovae 60 quasars 60 WM Keck Observatory 60 microlensing 60 NASA Cassini spacecraft 60 gravitational lensing 60 RHESSI 60 RS Ophiuchi 60 galaxy clusters 60 Galaxy Evolution 60 SN #A 60 Keck Telescope 59 supernovae 59 gamma ray bursts 59 Anisotropy Probe WMAP 59 WMAP satellite 59 gamma ray observatory 59 distant galaxies 59 Anisotropy Probe 59 ESO VLT 59 Keck telescope 59 Great Observatories 59 Evolution Explorer 59 ESO Very Large Telescope 59 gravitational microlensing 59 gamma ray burst 59 WMAP 58 GALEX 58 X ray emission 58 Keck Observatory 58 brightest supernova 58 UVOT 58 XMM Newton satellite 58 Explorer WISE 58 supernova explosion 58 supernova remnant 58 Subaru Telescope 57 distant quasars 57 Chandra Observatory 57 Kepler telescope 57 colliding galaxies 57 weak gravitational lensing 57 NASA Infrared Telescope 57 Keck telescopes 57 optical telescopes 57 fainter objects 57 NASA Cassini 57 Keck Interferometer 57 X ray telescope 57 GRBs 57 Fomalhaut b 57 Gemini Observatory 57 active galactic nuclei 57 faint galaxies 57 NASA ESA Hubble 57 NASA Kepler 57 distant galaxy 57 Cosmic Background Explorer 57 supernova 56 ESA Integral 56 VIRTIS 56 Astronomers 56 galaxies 56 Geminga 56 supernova remnants 56 Astrophysical Research 56 Moderate Resolution Imaging 56 Type Ia supernova 56 Fermi LAT 56 starburst galaxies 56 Nasa Kepler 56 CoRoT satellite 56 NASA Far Ultraviolet 56 microlensing events 56 Multi Object Spectrometer 56 magnetars 56 Galileo spacecraft 56 Mauna Kea Hawaii 56 ROSAT 56 HARPS instrument 56 Planetary Transits 56 GRB # 56 Orion Nebula 56 Multi Object Spectrograph 56 RS Oph 56 GRB #B 56 astronomical objects 55 Astrophysicists 55 Planck satellite 55 Near Infrared Camera 55 Extrasolar Planet Search 55 quasar 55 NASA Cosmic Background 55 HUDF 55 neutron star 55 Active Galactic Nuclei 55 Using ESO Very 55 elliptical galaxies 55 supernovas 55 constellation Carina 55 gravitational lenses 55 OGLE TR #b 55 Observatory Very 55 pulsars 55 Spectrograph 55 astronomical observations 55 Nikku Madhusudhan 55 Trifid Nebula 55 Lunar Reconnaissance Orbiter LRO 55 WISE infrared 55 Submillimeter Array 55 XMM Newton X ray 55 NASA Voyager spacecraft 55 infrared observatory 55 gravitational lens 55 inch Samuel Oschin 55 astrophysicists 55 Gemini telescopes 55 extrasolar planets 55 NASA Hubble Space 55 gravitational radiation 55 type Ia supernovae 55 Crab Nebula 54 planets orbiting distant 54 Infrared Thermal Imaging Spectrometer 54 Omega Centauri 54 Field Imager 54 blazars 54 galaxy cluster 54 Area Telescope LAT 54 distant quasar 54 Cassini Huygens 54 merging galaxies 54 SN #gy 54 gravitational waves 54 Hubble Near Infrared 54 starburst galaxy 54 SDSS II 54 globular clusters 54 Fermi Telescope 54 Hanny Voorwerp 54 Herschel Space 54 Interstellar Boundary Explorer 54 G#.# +#.# 54 extrasolar 54 Observatory STEREO 54 exoplanets orbiting 54 comet nucleus 54 cosmic microwave background 54 infrared telescope 54 accretion disks 54 Telescope 54 Virgo Cluster 54 occultations 54 Ulysses spacecraft 54 OGLE 54 Orbiter LRO 54 Optical Gravitational Lensing Experiment 54 elliptical galaxy NGC 54 SINFONI 54 spectroscopic 54 Compact Reconnaissance Imaging Spectrometer 54 Cosmic Microwave Background CMB 54 earthshine 54 AGNs 54 WISE telescope 54 Infrared Pathfinder Satellite 54 ESA Envisat satellite 54 Hubble Space Telescopes 54 CfA 54 BLG #Lb 54 Cassini Huygens spacecraft 54 NASA Lunar Reconnaissance 54 ESO telescopes 54 HARPS spectrograph attached 54 planets orbiting 54 solar corona 54 X ray wavelengths 53 telescopes astronomers 53 exoplanet 53 Astrophysical Journal 53 HESS telescopes 53 novae 53 Cosmic Microwave Background 53 Digitized Sky Survey 53 Wilkinson Microwave Probe 53 Saturn moon Enceladus 53 IBEX spacecraft 53 galaxy M# [002] 53 Pluto Charon 53 Deep Impact eXtended Investigation 53 radial velocity 53 GRB# 53 Hubble Space Telescope 53 Sagittarius Window Eclipsing 53 HIRES spectrometer 53 Coma Cluster 53 transiting exoplanets 53 infrared interferometry 53 SN #C 53 X ray afterglow 53 gaseous planet 53 Climate Experiment GRACE 53 planetary Transits 53 Red Rectangle 53 astrophysical objects 53 spatially resolved 53 redshift 53 spectroscopic measurements 53 Southern Observatory ESO 53 Surveys ACS 53 orbiting Saturn 53 visit http:/saturn.jpl.nasa.gov 53 discover Fomalhaut 53 Epsilon Aurigae 53 afterglows 53 Deep Field HUDF 53 Corot 7b 53 planet orbiting 53 stellar occultations 53 radio occultation 53 Orbiter MRO 53 Cassini flyby 53 Solar TErrestrial RElations Observatory 53 filamentary structure 53 detect gravitational waves 53 galaxy formation 53 barred spiral galaxy 53 planemos 53 extrasolar planet 53 Subaru telescope 53 Hubble Ultra 53 Wolszczan 53 exoplanets 53 Type Ia supernovae 53 X ray spectrometer 53 astrometry 53 telescopic observations 53 Convection Rotation 53 Cat Paw Nebula 53 Triangulum Galaxy 53 telescopes 53 Crab Pulsar 53 reionization 53 galaxies collide 53 Spitzer infrared spectrograph 52 ultraviolet imaging spectrograph 52 Space Telescope GLAST 52 VLTI 52 Bug Nebula 52 Kuiper belt objects 52 NuSTAR 52 Astrophysics Cambridge Mass. 52 CMB radiation 52 Herschel Space Telescope 52 SNfactory 52 Laser Interferometer Gravitational Wave 52 extrasolar planetary systems 52 Mössbauer 52 orbiting gamma ray 52 protoplanetary disks 52 Tod Strohmayer 52 millisecond pulsars 52 Astrophysics MOA 52 submillimetre 52 Interferometer 52 Saturn rings 52 pulsar 52 ESA Planck 52 EPOCh 52 astrophysical phenomena 52 interferometry 52 orbiting observatories 52 cosmic phenomena 52 noctilucent clouds 52 SEGUE 52 galaxy M# [001] 52 KBOs 52 neutron stars 52 MARSIS 52 Saturnian moon 52 ESO astronomer 52 Microlensing 52 coronagraph 52 X ray binary 52 Telescope BAT 52 heavily cratered 52 infrared mapping spectrometer 52 polarimetry 52 spiral galaxy NGC 52 SDSS III 52 magnetar 52 Extragalactic 52 PSR J# 52 Resolution Stereo Camera 52 Space Infrared Telescope 52 Andromeda galaxy 52 Earthlike planets 52 Cosmic Background Explorer COBE 52 cosmic cannibal 52 X ray Telescope XRT 52 Exoplanets 52 sunlike stars 52 Reflection Radiometer 52 Astrophysics 52 Upsilon Andromedae 52 binary quasar 52 Dumbbell Nebula 52 millisecond pulsar 52 UKIRT 52 Milky Way Galaxy 52 infrared telescopes 52 orbiting Hubble Space Telescope 52 telescope 52 dwarf galaxy 52 Relations Observatory STEREO 52 Helix Nebula 52 supergiant star 52 planetary nebulae 52 ESA Herschel 52 cometary dust 52 Spitzer infrared 52 Kepler Space Telescope 52 HiRISE camera aboard 52 Cepheids 52 MPG ESO 52 intrinsic brightness 52 Kepler Mission 51 blazar 51 Advanced Spaceborne Thermal Emission 51 Gamma Ray 51 OMEGA instrument 51 Lyman alpha 51 spacecraft Cassini 51 cosmological distances 51 AU Mic 51 stellar seismology 51 Science Experiment HiRISE 51 PSR B# +# 51 proto galaxies 51 adaptive optics 51 protostars 51 exoplanetary 51 Exoplanet 51 galaxy NGC 51 NASA Lunar Prospector 51 mu Arae 51 Astrophysical 51 Lunar Prospector 51 galactic clusters 51 Planck telescope 51 INTEGRAL satellite 51 gamma ray flares 51 star Gliese 51 DEM L# 51 globular star 51 planets orbiting sun 51 VIRTIS instrument 51 gamma ray 51 planetary nebulas 51 COROT 51 Milky Way galaxy 51 THEMIS satellites 51 supermassive black hole 51 Type 1a supernovae 51 Ring Nebula 51 Lagoon Nebula 51 Cassini 51 moons orbiting 51 XMM Newton observations 51 Vikhlinin 51 Carina Nebula 51 AB Aurigae 51 distant supernovas 51 Herschel telescope 51 Solar Dynamics 51 cosmologists 51 infrared spectrograph 51 infrared astronomy 51 eclipsing binary 51 GJ #b [001] 51 X ray pulses 51 CloudSat 51 Comet Holmes 51 VLBA 51 NASA Great Observatories 51 Mini SAR 51 accretion disk 51 Mars Orbiter 51 Interior Laboratory GRAIL 51 moon Mab 51 auroras 51 MERIS 51 NASA LCROSS 51 Neil Gehrels 51 foreground galaxy 51 Cosmologists 51 Great Observatories Origins 51 Hinode 51 redshifts 51 SPICAM 51 LIGO 51 Hubble Space Telescope HST 51 cosmic microwave radiation 51 ESO Paranal Observatory 51 APXS 51 SWIFT J#.# 51 gravitational interactions 51 Cloud Aerosol Lidar 51 Burst Alert 51 red supergiants 51 Descent Imager Spectral Radiometer 51 Milky Way halo 51 sunlike star 51 spherules 51 NASA Stardust spacecraft 51 Eagle Nebula 51 extragalactic 51 optical interferometry 51 NASA THEMIS 51 Butterfly Nebula 51 globulars 51 EPOXI 51 HD #b [002] 51 Aram Chaos 51 nebulae 51 telescope atop Mauna 51 Pierre Auger Observatory 51 CALIPSO 51 quark gluon plasma 51 European Synchrotron Radiation 51 cosmic ray observatory 51 Astrophysical Journal Letters 51 extrasolar planets orbiting 51 magnetospheric 51 P/# A2 51 aurorae 51 radial velocity technique 51 Adaptive Optics 51 Beta Pictoris b 51 EVLA 51 type Ia supernova 51 X ray Timing 51 La Silla observatory 51 EPOXI mission 51 WIYN 51 Hinode spacecraft 50 NASA EPOXI mission 50 DEEP2 50 rocky planets 50 planets circling 50 NASA Tropical Rainfall 50 GROND 50 interferometers 50 Heterodyne Instrument 50 luminous galaxies 50 interacting galaxies 50 supermassive black holes 50 dwarf galaxies 50 Comet 9P/Tempel 1 50 brown dwarfs 50 sized planets orbiting 50 protostar 50 SOAR telescope 50 exo planet 50 multiband imaging photometer 50 AKARI 50 Envisat satellite 50 STScI 50 Compton Gamma Ray 50 Observatory SDO 50 transiting exoplanet 50 planets orbiting stars 50 Solar Terrestrial Relations 50 spiral nebulae 50 STEREO spacecraft 50 Solar System 50 galactic cosmic rays 50 elliptical galaxy 50 PASADENA Calif. Astronomers 50 Harvard exoplanet hunter 50 LOFAR 50 Viking landers 50 substorm 50 radar interferometry 50 Bullet Cluster 50 Helix nebula 50 Investigation DIXI 50 Andromeda Galaxy 50 Gravitational lensing 50 Moderate Resolution 50 V# Mon 50 exo planets 50 rocky extrasolar planet 50 cosmological parameters 50 Cassini spacecraft 50 NASA twin STEREO 50 Lunar CRater Observation 50 Veil Nebula 50 super Earths 50 Caltech astronomer 50 supercomputer simulations 50 Hubble Telescope 50 super perigee moon 50 Swift Ultraviolet Optical 50 supermassive 50 Explorer GALEX 50 SOHO spacecraft 50 NASA STEREO 50 Mars Pathfinder lander 50 Imaging Spectroradiometer MODIS instrument 50 retrograde orbit 50 Cosmic Evolution 50 Nasa spacecraft 50 celestial phenomena 50 Giovanni Cassini 50 National Astronomical Observatory 50 AERONET 50 HARPS spectrograph 50 Henize #-# 50 Comet #P 50 Instrument OMI 50 polar vortex 50 electron diffraction 50 Resolution Imaging 50 #gy 50 NASA Aqua 50 AMIE camera 50 Small Magellanic Cloud 50 Aqua satellite 50 Mars CRISM 50 MODIS 50 radial velocity method 50 solar flares 50 Io Europa 50 Suzaku X ray 50 Neutron Spectrometer 50 cosmic rays 50 Gravitational waves 50 Seyfert galaxies 50 called gravitational microlensing 50 Earth Observation satellites 50 particle analyzers 50 galaxy redshift 50 relativistic jets 50 NASA MESSENGER spacecraft 50 Thermal Emission 50 Space Telescopes 50 ULIRGs 49 Tropical Rainfall Measuring 49 star Beta Pictoris 49 sterile neutrino 49 NASA WMAP 49 globular cluster 49 Adam Riess 49 numerical simulations 49 radar altimetry 49 moon permanently shadowed 49 Moon Mineralogy Mapper 49 field Infrared Survey 49 Gamma ray Burst 49 Comet Hartley 2 49 GLAST 49 supernova SN 49 retrograde orbits 49 TRMM satellite 49 planetary astronomer 49 Planetary Fourier Spectrometer PFS 49 moon Io 49 Cassini radar 49 Mars Reconnaissance Orbiter MRO 49 martian meteorites 49 ESA ERS 49 HD#b 49 Alpha Particle 49 spacecraft flyby 49 Cygnus X 49 Palomar Observatory 49 X ray Telescope 49 LORRI 49 supersymmetric particles 49 ejecta 49 Type Ia 49 laser altimeter 49 Paranal Observatory 49 Harvard Smithsonian CfA 49 Galilean satellites 49 neutron spectrometer 49 orbiting Hubble telescope 49 Cassini ultraviolet 49 cosmic ray 49 UVIS 49 proplyds 49 Spectroradiometer MODIS 49 KH #D 49 supergiant stars 49 comet McNaught 49 Zeta Ophiuchi 49 Muchachos Observatory 49 Cerro Paranal 49 Landsat satellite 49 Solar Dynamics Observatory 49 Neutron Detector 49 Voyager spacecraft 49 NASA COBE satellite 49 Eta Carinae 49 Cassini flybys 49 Higgs bosons 49 Hawaii van Dokkum 49 IceCube 49 protoplanetary disk 49 constellation Cassiopeia 49 dust enshrouded 49 Saturn moons Enceladus 49 ESA Mars 49 ESA SMART 49 multiwavelength 49 Composite Infrared Spectrometer 49 lunar crust 49 Trojan asteroids 49 NASA Gamma ray 49 magnetic reconnection 49 TGFs 49 Venusian atmosphere 49 SIM PlanetQuest 49 Explorer IBEX 49 SeaWiFS 49 Resolution Imaging Spectrometer 49 spacecraft orbiting 49 Doppler measurements 49 HiRISE camera 49 COROT 7b 49 gamma ray telescopes 49 Milky Way 49 sun corona 49 Mimas 49 Cassini Imaging 49 HiRISE images 49 Mercury flyby 49 planets comets 49 AMSR E 49 Tycho supernova remnant 49 Kuiper Belt Objects 49 Advanced Synthetic Aperture 49 HiRISE image 49 Stephan Quintet 49 refurbished Hubble Space 49 spectrographic 49 neutral mass spectrometer 49 Alex Filippenko 49 Beta Pictoris 49 infrared spectra 49 ESO PR 49 Epsilon Eridani 49 Edwin Hubble 49 Ranging spacecraft 49 Kuiper belt object 49 Large Telescope 49 optical microscopy 49 Pan STARRS 49 NASA Mars Reconnaissance 49 ESO telescope 49 Antennae Galaxies 49 submillimeter galaxies 49 star Fomalhaut 49 coronal loops 49 Extraterrestrial Physics 49 Spectrometers 49 astrometric 49 cometary 49 Spitzer infrared telescope 49 NEOWISE 49 Gal Yam 49 Comet Hartley 49 Sky Survey SDSS 49 geochemists 49 auroral emissions 49 Orbiting Carbon Observatory 49 MicroFUN 49 SN#A 49 TrES 4 49 STEREO 49 Deep Impact comet 49 gamma ray emission 49 #P/Churyumov-Gerasimenko 49 supernova explosions 49 SIRTF 49 Harvard Smithsonian 49 comet flyby 49 Magellanic Clouds 49 Gamma ray bursts 49 SN #E 49 stellar nurseries 49 planets 49 exoplanet hunter 49 Planetary Science Institute 49 astronomical telescope 49 permanently shadowed craters 49 planetesimals 49 Richard Mushotzky 49 CERN experiments 49 HD# [002] 49 muon neutrino 49 Krimigis 49 infrared wavelengths 49 Galilean moons 49 UA Lunar 49 Extrasolar Planet Observation 49 Cygnus Lyra region 49 High Accuracy Radial 49 Reflection Radiometer ASTER 48 Planetary Camera 2 48 WASP #b 48 zodiacal light 48 Tarantula Nebula 48 Mission TRMM satellite 48 Japan NAOJ 48 planetary missions 48 smallest exoplanet 48 galactic mergers 48 submillimeter wavelengths 48 Supernova #A 48 YORP effect 48 Viking Orbiter 48 Hot Jupiters 48 Total Ozone Mapping 48 lobate scarps 48 magma ocean 48 particle detector 48 comets 48 spectroscopically 48 cryovolcanism 48 NOAO 48 LCROSS 48 neutrinos 48 Infrared Astronomical Satellite 48 GJ#b 48 Imaging Spectrometer 48 Saturn auroras 48 giant elliptical galaxy 48 circumstellar 48 VISTA telescope 48 THEMIS spacecraft 48 planets atmospheres 48 NASAs 48 Caloris 48 RRATs 48 proton collisions 48 Observatory telescope 48 nebula 48 SN #D 48 KAGUYA 48 gravitationally lensed 48 Martian crater 48 Large Magellanic Cloud 48 NASA Mars Odyssey 48 electron neutrinos 48 protoplanet 48 UCO Lick 48 David Spergel 48 gamma ray bursts GRBs 48 mineralogical composition 48 comet 48 Lunar Laser Ranging 48 ringed planet 48 Imaging Spectroradiometer MODIS 48 Pancam 48 moonlets 48 spectroscopic analysis 48 HM Cancri 48 NASA QuikScat satellite 48 NASA ICESat 48 gravity warps 48 millimeter wavelengths 48 DIXI 48 microquasar 48 Array ALMA 48 galaxies nebulae 48 GRB #A 48 InSAR 48 WFC3 48 http:/www.nasa.gov/cassini 48 Surface Composition Spectrometer 48 NOAA GOES 48 Deep Impact probe 48 Hipparcos 48 interstellar cloud 48 Envisat 48 BBSNews #-#-# NASA 48 La Silla Observatory 48 Wolfgang Brandner 48 Pieter van Dokkum 48 asteroid Eros 48 Lunar Reconnaissance Orbiter Camera 48 Orion nebula 48 particle detectors 48 Radioastronomy 48 NASA Kepler spacecraft 48 interstellar clouds 48 microscopy technique 48 Martian meteorites 48 galactic collisions 48 Planck spacecraft 48 hydrated minerals 48 muon neutrinos 48 Wide Angle Search 48 Mars Reconnaissance Orbiter 48 gamma rays 48 Sensing Satellite LCROSS 48 moon Charon 48 orbiting telescopes 48 Type Ia supernovas 48 constellation Ursa Major 48 Black Holes 48 celestial object 48 WFPC2 48 brown dwarf 48 Boethin 48 planet Gliese #g 48 KamLAND 48 Ultraviolet Optical Telescope 48 ESA Cluster 48 stellar occultation 48 Antenna LISA 48 Grillmair 48 La Silla Chile 48 N. Rathnasree 48 http:/saturn.jpl.nasa.gov 48 Brookhaven Relativistic Heavy 48 Saturn moons 48 intracluster 48 comet Lulin 48 Submillimeter 48 Spectroradiometer 48 volcanic moon Io 48 HiRISE 48 synchrotron x ray 48 Saturnian moon Titan 48 planetary nebula 48 Saturn magnetosphere 48 DISR 48 HRSC 48 red supergiant 48 reionization epoch 48 optical telescope 48 Hobby Eberly Telescope 48 GJ #b [002] 48 Space Station Status 48 Lick Observatory 48 jovian 48 LROC 48 Paranal Chile 48 ESA ASI 48 X ray emitting 48 TNOs 48 planets astronomers 48 Deep Impact Extended 48 Hubble 48 Gamma ray 48 NICMOS 48 QQ# 48 Earth orbiting satellites 48 Voorwerp 48 XMM Newton observatory 48 Mission SRTM 48 BP Psc 48 constellation Centaurus 48 planet Uranus 48 phyllosilicates 48 Einstein theory 48 gravitational interaction 48 High Resolution Imaging 48 proto cluster 48 particle smasher 48 Shuttle Radar Topography 48 Optical Telescope 48 MESSENGER MErcury Surface 48 ESA Envisat 48 Viking Lander 48 NASA Spacecraft 48 Sagittarius B2 48 orbiting observatory 48 Cassini ion 48 Samuel Oschin Telescope 48 Envisat satellites 48 energetic gamma rays 48 SDSS telescope 48 distant galaxy clusters 48 noctilucent 47 MIT neuroscientists 47 circumstellar disk 47 infrared imager 47 Infrared Astronomy 47 CMEs 47 faraway galaxies 47 Stanford Synchrotron Radiation Lightsource 47 axions 47 cosmic magnifying glass 47 X ray absorption spectroscopy 47 planets Uranus 47 proto planetary disks 47 Geminids 47 Orionids 47 Katzman Automatic 47 Diviner instrument 47 icy moons 47 lunar topography 47 astrophysical 47 COBE 47 Kuiper belt 47 Pierre Auger 47 Hubble Captures 47 Manchester Jodrell Bank 47 backscattered 47 moonlet 47 Jovian atmosphere 47 spiral galaxy 47 transiting planets 47 exoplanets planets 47 periodic dimming 47 submillimeter 47 ESO La Silla 47 gravitationally bound 47 AATSR 47 Supernovae 47 Stefan Immler 47 starquakes 47 #P/Holmes 47 radiotelescope 47 Lick Carnegie Exoplanet 47 Carnegie Observatories 47 Telescope LSST 47 orbiting 47 Harvard Smithsonian Astrophysical 47 Cancri e 47 smallest exoplanets 47 TSN PZ camera 47 Gamma ray Large 47 NASA Lunar CRater 47 VLBI 47 Viking orbiters 47 THEMIS 47 Virgo cluster 47 Thermal Emission Spectrometer 47 lunar craters 47 Neutron stars 47 planetary embryos 47 orbited Jupiter 47 Hale Bopp 47 Photoacoustic 47 CRISM 47 planets orbits 47 dwarf spheroidal galaxies 47 colliders 47 Solar Orbiter 47 Neutral Mass Spectrometer 47 Uranus Neptune 47 Gamma ray burst 47 Spacewatch 47 Rayleigh scattering 47 positrons 47 polar stratospheric 47 Reconnaissance Orbiter 47 Elenin 47 convective clouds 47 Kepler spacecraft 47 SNR #-#.# 47 gamma ray burst GRB 47 HETE 47 Volatile Evolution 47 double helix nebula 47 fading afterglow 47 Earthshine 47 inhabitable planets 47 GigaGalaxy Zoom